The field of this invention is gas lift valves. Through the years, it has been accepted practice to make gas lift valves with a relatively long valve stem extending from a bellows to a valve seat, such as illustrated in U.S. Pat. Nos. 2,465,060; 3,194,175 and 3,424,099. In some instances, the spring for closing the valve has been located below the bellows as in said U.S. Pat. Nos. 2,465,060 and 3,194,175 and in other cases, the spring has been located above the bellows, but in all instances, so far as known, the valve stem has been long and has been subject to the undesirable characteristics of bowing and corkscrewing which results in dragging on the spring or improper seating of the valve, or both. Since the opening and closing of gas lift valves must be closely controlled for effective gas lifting operations, such deficiencies reduce effective gas lift operations and reduce the efficiency of operation, resulting in lower production of the oil from the well.
Also, so far as know, and as illustrated by the foregoing patents, the adjustment of the spring pressure has been difficult and time-consuming because the valves have had to be substantially disassembled to accomplish such adjustment, and sometimes the disassembly and reassembly must be repeated to get the proper adjustment. Since adjustments become necessary with changes in the use of the valves and well conditions, the necessity of disassembly and reassembly of the prior art valves for adjustment has been highly undesirable.